This invention relates generally to processing computer tomography (CT) datasets, and more particularly, to detecting contours of elongated structures such as blood vessels within CT datasets.
Cardiovascular related deaths constitute more than 500,000 people annually in the USA, and much more globally. A major portion of the deaths are attributed to coronary artery disease, where the chief culprit is the build up of plaque, such as soft plaque and its ruptures, as well as hard plaque or calcification.
Typically in x-ray or non-contrasted CT studies, soft plaque is not easily detectable. Calcified plaque, therefore, has been used as a surrogate for the presence of soft plaque, based on the reasoning that calcified plaque is the by-product of ruptured plaque. Coronary plaque has been classified into six stages according to the Stary scale. According to general consensus, it is crucial to determine the plaque in stages 4 and 5 as the plaque constitutes critical vulnerable plaque and could lead to rupture or dislodging of the plaque, causing blockages and leading to myocardial infarction. Plaque and its constituency may be determined by IntraVascular Ultrasound (IVUS). However, the procedure is only performed on symptomatic patients due to its invasive nature. Unfortunately, symptomatic patients are already at an advanced stage and past non-invasive therapy options.
Newer scanning technologies, such as Cardiac Virtual CT (VCT) and associated increases in spatial and temporal resolution have made it possible to image a contrasted study of the heart which is gated to mitigate heart motion. Using these images, it is possible to distinguish soft plaque from lumen (the vessel wall) and from calcification. However, automated methods do not exist and thus standardization and productivity suffer due to the volume of data to be reviewed and manually processed.
Therefore, a need exists for automating aspects of locating vessel walls to better enable computation of metrics associated with the vessel, as well as with any deposits within the vessel. Certain embodiments of the present invention are intended to meet these needs and other objectives that will become apparent from the description and drawings set forth below.